Associate Professor Phil Battley

Associate Professor

Institute of Agriculture and Environment

I work principally on the biology of migratory shorebirds, particularly those that make huge trans-hemispheric journeys. Following an MSc looking at the ecology of shorebirds at the end of Farewell Spit, the long sandspit at the top of New Zealand's South Island, I moved to Australia. My PhD work was on the ecophysiology and behaviour of migrating Great Knots at Broome, NW Australia, though I also sampled knots caught upon arrival from migration at the mouth of the Yangtze River, China. Back in New Zealand my research has focused on national and international movements of individual shorebirds, the timing of migration, and plumage colouration. I do have broader interests in ornithology, however, and students have worked on a range of species and topics including Kereru, Rockhopper Penguins and polychaete worms.

I am a member of the National Oiled Wildlife Response Team, and on the editorial board for Ibis, the journal of the British Ornithologists' Union, and The Stilt (Australasian Wader Studies Group).

I am interested in ornithology in general, but specifically in bird migration, particularly shorebirds along the East Asian-Australasian Flyway. This work involves remote tracking of Bar-tailed Godwits and Red Knots from New Zealand, and investigating the molecular basis to godwit migration timing in a Marsden-funded project with Dr Andrew Fidler (Cawthron Inst.).

Keywords

Research Projects

Summary of Research Projects

Position

Current

Completed

Project Leader

3

8

Current Projects

Project Title: The genetics and epigenetics of bird migration timing

The epic migrations of birds toward distant breeding grounds in anticipation of seasonally-available resources reveal an ability to accurately `tell time¿. Moreover, individuals may migrate on consistently different dates, indicating the existence of sensitive, individually-tuned timing mechanisms. This is particularly well-characterised in bar-tailed godwits, long-distance migrant shorebirds that travel from New Zealand to breed in Alaska. Individuals embark on northward migration across 30 days but, remarkably, each bird typically leaves in the same week annually with some birds leaving within just a day or two year after year. We hypothesise that these behavioural differences reflect individual variation in responses to photoperiod changes, arising in part from variation in genes involved in the circadian core oscillator (CCO). We will investigate genetic and epigenetic (DNA methylation) variation in candidate genes central to the CCO (BMAL1, CLOCK) or its output (AANAT) and in a non-CCO gene that may relate to migratory propensity (ACDYAP1). We will look for associations between migration time and individual genotype/methylation at these four loci, correcting for underlying population structure using microsatellites. This work will provide insights into the mechanisms behind vertebrate photoperiodic responses as well as the ecological and evolutionary significance of genetic and epigenetic variation in natural populations.

Completed Projects

The issue of how animals balance conflicting demands is central to the study of animal ecology and evolution. Such issues may be particularly acute for animals whose movements set limits to the time that can be spent preparing for certain activities. For birds that migrate long distances, for instance, a prebreeding moult is typically undertaken largely on the non-breeding grounds. As the longest-migrating birds are also the earliest to start migrating, they may be more constrained in their opportunities for moult than shorter-distance migrants. Ideally, the longest-distance migrants might invest in stronger feathers that can resist the wear and tear incurred over up to four months and 17,000 km of travel. But their earlier departure on migration may in fact result in the opposite. We attempted to tease apart how the apparent colour of the breeding plumage varies between species and populations of shorebirds, in relation to the investment of melanins in the feathers and the amount of wear the feather has experienced. We collected feathers from five species of migratory shorebird along two major flyways (New Zealand, Australia, China and Alaska; The Netherlands, Germany and Norway), measured aspects of the plumage colouration via spectrometry and the feather structure by microscopy, and studied the moult and migration strategies of the Bar-tailed Godwits that `winter¿ in New Zealand..